The London Borough of Tower Hamlets is a London borough covering much of the traditional East End. It was formed in 1965 from the merger of the former metropolitan boroughs of Stepney, Poplar, and Bethnal Green. 'Tower Hamlets' was originally an alternative name for the historic Tower Division; the area of south-east Middlesex, focused on (but not limited to) the area of the modern borough, which owed military service to the Tower of London.

The borough lies on the north bank of the River Thames immediately east of the City of London, and includes much of the redeveloped Docklands area. Some of the tallest buildings in London occupy the centre of the Isle of Dogs in the south of the borough. A part of the Queen Elizabeth Olympic Park is in Tower Hamlets.

The 2019 mid-year population for the borough is estimated at 324,745. British Bangladeshis at 32% form the largest ethnic group. The 2011 census showed Tower Hamlets to have the highest proportion of Muslims of any English local authority and that Muslims heavily outnumbered Christians. The borough has more than 40 mosques, Islamic centres and madrasahs, including the East London Mosque, Britain's largest. Brick Lane's restaurants, neighbouring street market and shops provide the largest range of Bangladeshi cuisine, woodwork, carpets and clothes in Europe. The Lane is also a major centre of hipster subculture.

In 2017 a joint study by Trust for London and New Policy Institute found Tower Hamlets to be the 2nd most deprived London borough (after Barking and Dagenham) based on an average calculated across a range of indicators; with high rates of poverty, child poverty, unemployment and pay inequality compared to other London boroughs. However, it has the lowest gap for educational outcomes at secondary level.

The local authority is Tower Hamlets London Borough Council.